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4803 commits

Author SHA1 Message Date
Ondrej Mosnacek
b17dd53cac selinux: fix NULL-pointer dereference when hashtab allocation fails
commit dc27f3c5d1 upstream.

When the hash table slot array allocation fails in hashtab_init(),
h->size is left initialized with a non-zero value, but the h->htable
pointer is NULL. This may then cause a NULL pointer dereference, since
the policydb code relies on the assumption that even after a failed
hashtab_init(), hashtab_map() and hashtab_destroy() can be safely called
on it. Yet, these detect an empty hashtab only by looking at the size.

Fix this by making sure that hashtab_init() always leaves behind a valid
empty hashtab when the allocation fails.

Cc: stable@vger.kernel.org
Fixes: 03414a49ad ("selinux: do not allocate hashtabs dynamically")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-26 10:39:21 +01:00
Kees Cook
eaafc59005 fortify: Explicitly disable Clang support
commit a52f8a59ae upstream.

Clang has never correctly compiled the FORTIFY_SOURCE defenses due to
a couple bugs:

	Eliding inlines with matching __builtin_* names
	https://bugs.llvm.org/show_bug.cgi?id=50322

	Incorrect __builtin_constant_p() of some globals
	https://bugs.llvm.org/show_bug.cgi?id=41459

In the process of making improvements to the FORTIFY_SOURCE defenses, the
first (silent) bug (coincidentally) becomes worked around, but exposes
the latter which breaks the build. As such, Clang must not be used with
CONFIG_FORTIFY_SOURCE until at least latter bug is fixed (in Clang 13),
and the fortify routines have been rearranged.

Update the Kconfig to reflect the reality of the current situation.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/lkml/CAKwvOd=A+ueGV2ihdy5GtgR2fQbcXjjAtVxv3=cPjffpebZB7A@mail.gmail.com
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-21 13:46:35 +01:00
Tom Rix
851b622e7b apparmor: fix error check
[ Upstream commit d108370c64 ]

clang static analysis reports this representative problem:

label.c:1463:16: warning: Assigned value is garbage or undefined
        label->hname = name;
                     ^ ~~~~

In aa_update_label_name(), this the problem block of code

	if (aa_label_acntsxprint(&name, ...) == -1)
		return res;

On failure, aa_label_acntsxprint() has a more complicated return
that just -1.  So check for a negative return.

It was also noted that the aa_label_acntsxprint() main comment refers
to a nonexistent parameter, so clean up the comment.

Fixes: f1bd904175 ("apparmor: add the base fns() for domain labels")
Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18 14:04:22 +01:00
Tetsuo Handa
d337537181 smackfs: use netlbl_cfg_cipsov4_del() for deleting cipso_v4_doi
[ Upstream commit 0934ad42bb ]

syzbot is reporting UAF at cipso_v4_doi_search() [1], for smk_cipso_doi()
is calling kfree() without removing from the cipso_v4_doi_list list after
netlbl_cfg_cipsov4_map_add() returned an error. We need to use
netlbl_cfg_cipsov4_del() in order to remove from the list and wait for
RCU grace period before kfree().

Link: https://syzkaller.appspot.com/bug?extid=93dba5b91f0fed312cbd [1]
Reported-by: syzbot <syzbot+93dba5b91f0fed312cbd@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: 6c2e8ac095 ("netlabel: Update kernel configuration API")
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18 14:04:10 +01:00
Tetsuo Handa
c11aecbe05 smackfs: use __GFP_NOFAIL for smk_cipso_doi()
[ Upstream commit f91488ee15 ]

syzbot is reporting kernel panic at smk_cipso_doi() due to memory
allocation fault injection [1]. The reason for need to use panic() was
not explained. But since no fix was proposed for 18 months, for now
let's use __GFP_NOFAIL for utilizing syzbot resource on other bugs.

Link: https://syzkaller.appspot.com/bug?extid=89731ccb6fec15ce1c22 [1]
Reported-by: syzbot <syzbot+89731ccb6fec15ce1c22@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18 14:03:59 +01:00
Pawan Gupta
3fac6feca9 smackfs: Fix use-after-free in netlbl_catmap_walk()
[ Upstream commit 0817534ff9 ]

Syzkaller reported use-after-free bug as described in [1]. The bug is
triggered when smk_set_cipso() tries to free stale category bitmaps
while there are concurrent reader(s) using the same bitmaps.

Wait for RCU grace period to finish before freeing the category bitmaps
in smk_set_cipso(). This makes sure that there are no more readers using
the stale bitmaps and freeing them should be safe.

[1] https://lore.kernel.org/netdev/000000000000a814c505ca657a4e@google.com/

Reported-by: syzbot+3f91de0b813cc3d19a80@syzkaller.appspotmail.com
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18 14:03:53 +01:00
Austin Kim
c7400e2ec8 evm: mark evm_fixmode as __ro_after_init
commit 32ba540f3c upstream.

The evm_fixmode is only configurable by command-line option and it is never
modified outside initcalls, so declaring it with __ro_after_init is better.

Signed-off-by: Austin Kim <austin.kim@lge.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-18 14:03:46 +01:00
Ondrej Mosnacek
db04fb4111 selinux: fix race condition when computing ocontext SIDs
commit cbfcd13be5 upstream.

Current code contains a lot of racy patterns when converting an
ocontext's context structure to an SID. This is being done in a "lazy"
fashion, such that the SID is looked up in the SID table only when it's
first needed and then cached in the "sid" field of the ocontext
structure. However, this is done without any locking or memory barriers
and is thus unsafe.

Between commits 24ed7fdae6 ("selinux: use separate table for initial
SID lookup") and 66f8e2f03c ("selinux: sidtab reverse lookup hash
table"), this race condition lead to an actual observable bug, because a
pointer to the shared sid field was passed directly to
sidtab_context_to_sid(), which was using this location to also store an
intermediate value, which could have been read by other threads and
interpreted as an SID. In practice this caused e.g. new mounts to get a
wrong (seemingly random) filesystem context, leading to strange denials.
This bug has been spotted in the wild at least twice, see [1] and [2].

Fix the race condition by making all the racy functions use a common
helper that ensures the ocontext::sid accesses are made safely using the
appropriate SMP constructs.

Note that security_netif_sid() was populating the sid field of both
contexts stored in the ocontext, but only the first one was actually
used. The SELinux wiki's documentation on the "netifcon" policy
statement [3] suggests that using only the first context is intentional.
I kept only the handling of the first context here, as there is really
no point in doing the SID lookup for the unused one.

I wasn't able to reproduce the bug mentioned above on any kernel that
includes commit 66f8e2f03c, even though it has been reported that the
issue occurs with that commit, too, just less frequently. Thus, I wasn't
able to verify that this patch fixes the issue, but it makes sense to
avoid the race condition regardless.

[1] https://github.com/containers/container-selinux/issues/89
[2] https://lists.fedoraproject.org/archives/list/selinux@lists.fedoraproject.org/thread/6DMTAMHIOAOEMUAVTULJD45JZU7IBAFM/
[3] https://selinuxproject.org/page/NetworkStatements#netifcon

Cc: stable@vger.kernel.org
Cc: Xinjie Zheng <xinjie@google.com>
Reported-by: Sujithra Periasamy <sujithra@google.com>
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-18 14:03:44 +01:00
Todd Kjos
0d9f4ae7cd binder: use cred instead of task for selinux checks
commit 52f8869337 upstream.

Since binder was integrated with selinux, it has passed
'struct task_struct' associated with the binder_proc
to represent the source and target of transactions.
The conversion of task to SID was then done in the hook
implementations. It turns out that there are race conditions
which can result in an incorrect security context being used.

Fix by using the 'struct cred' saved during binder_open and pass
it to the selinux subsystem.

Cc: stable@vger.kernel.org # 5.14 (need backport for earlier stables)
Fixes: 79af73079d ("Add security hooks to binder and implement the hooks for SELinux.")
Suggested-by: Jann Horn <jannh@google.com>
Signed-off-by: Todd Kjos <tkjos@google.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-18 14:03:36 +01:00
Tianjia Zhang
df19d95141 Smack: Fix wrong semantics in smk_access_entry()
[ Upstream commit 6d14f5c702 ]

In the smk_access_entry() function, if no matching rule is found
in the rust_list, a negative error code will be used to perform bit
operations with the MAY_ enumeration value. This is semantically
wrong. This patch fixes this issue.

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-18 13:40:18 +02:00
THOBY Simon
34d099a330 IMA: remove the dependency on CRYPTO_MD5
commit 8510505d55 upstream.

MD5 is a weak digest algorithm that shouldn't be used for cryptographic
operation. It hinders the efficiency of a patch set that aims to limit
the digests allowed for the extended file attribute namely security.ima.
MD5 is no longer a requirement for IMA, nor should it be used there.

The sole place where we still use the MD5 algorithm inside IMA is setting
the ima_hash algorithm to MD5, if the user supplies 'ima_hash=md5'
parameter on the command line.  With commit ab60368ab6 ("ima: Fallback
to the builtin hash algorithm"), setting "ima_hash=md5" fails gracefully
when CRYPTO_MD5 is not set:
	ima: Can not allocate md5 (reason: -2)
	ima: Allocating md5 failed, going to use default hash algorithm sha256

Remove the CRYPTO_MD5 dependency for IMA.

Signed-off-by: THOBY Simon <Simon.THOBY@viveris.fr>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
[zohar@linux.ibm.com: include commit number in patch description for
stable.]
Cc: stable@vger.kernel.org # 4.17
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-15 09:50:48 +02:00
Austin Kim
5cc1ee3135 IMA: remove -Wmissing-prototypes warning
commit a32ad90426 upstream.

With W=1 build, the compiler throws warning message as below:

   security/integrity/ima/ima_mok.c:24:12: warning:
   no previous prototype for ‘ima_mok_init’ [-Wmissing-prototypes]
       __init int ima_mok_init(void)

Silence the warning by adding static keyword to ima_mok_init().

Signed-off-by: Austin Kim <austin.kim@lge.com>
Fixes: 41c89b64d7 ("IMA: create machine owner and blacklist keyrings")
Cc: stable@vger.kernel.org
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-15 09:50:48 +02:00
Daniel Borkmann
d8c3859870 bpf: Add lockdown check for probe_write_user helper
commit 51e1bb9eea upstream.

Back then, commit 96ae522795 ("bpf: Add bpf_probe_write_user BPF helper
to be called in tracers") added the bpf_probe_write_user() helper in order
to allow to override user space memory. Its original goal was to have a
facility to "debug, divert, and manipulate execution of semi-cooperative
processes" under CAP_SYS_ADMIN. Write to kernel was explicitly disallowed
since it would otherwise tamper with its integrity.

One use case was shown in cf9b1199de ("samples/bpf: Add test/example of
using bpf_probe_write_user bpf helper") where the program DNATs traffic
at the time of connect(2) syscall, meaning, it rewrites the arguments to
a syscall while they're still in userspace, and before the syscall has a
chance to copy the argument into kernel space. These days we have better
mechanisms in BPF for achieving the same (e.g. for load-balancers), but
without having to write to userspace memory.

Of course the bpf_probe_write_user() helper can also be used to abuse
many other things for both good or bad purpose. Outside of BPF, there is
a similar mechanism for ptrace(2) such as PTRACE_PEEK{TEXT,DATA} and
PTRACE_POKE{TEXT,DATA}, but would likely require some more effort.
Commit 96ae522795 explicitly dedicated the helper for experimentation
purpose only. Thus, move the helper's availability behind a newly added
LOCKDOWN_BPF_WRITE_USER lockdown knob so that the helper is disabled under
the "integrity" mode. More fine-grained control can be implemented also
from LSM side with this change.

Fixes: 96ae522795 ("bpf: Add bpf_probe_write_user BPF helper to be called in tracers")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-15 14:00:25 +02:00
Xiu Jianfeng
f4984f60ac selinux: correct the return value when loads initial sids
commit 4c156084da upstream.

It should not return 0 when SID 0 is assigned to isids.
This patch fixes it.

Cc: stable@vger.kernel.org
Fixes: e3e0b582c3 ("selinux: remove unused initial SIDs and improve handling")
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
[PM: remove changelog from description]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-12 13:22:16 +02:00
Tetsuo Handa
3780348c1a smackfs: restrict bytes count in smk_set_cipso()
commit 49ec114a6e upstream.

Oops, I failed to update subject line.

From 07571157c91b98ce1a4aa70967531e64b78e8346 Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Mon, 12 Apr 2021 22:25:06 +0900
Subject: smackfs: restrict bytes count in smk_set_cipso()

Commit 7ef4c19d24 ("smackfs: restrict bytes count in smackfs write
functions") missed that count > SMK_CIPSOMAX check applies to only
format == SMK_FIXED24_FMT case.

Reported-by: syzbot <syzbot+77c53db50c9fff774e8e@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-19 09:45:03 +02:00
Minchan Kim
f38371821c selinux: use __GFP_NOWARN with GFP_NOWAIT in the AVC
[ Upstream commit 648f2c6100 ]

In the field, we have seen lots of allocation failure from the call
path below.

06-03 13:29:12.999 1010315 31557 31557 W Binder  : 31542_2: page allocation failure: order:0, mode:0x800(GFP_NOWAIT), nodemask=(null),cpuset=background,mems_allowed=0
...
...
06-03 13:29:12.999 1010315 31557 31557 W Call trace:
06-03 13:29:12.999 1010315 31557 31557 W         : dump_backtrace.cfi_jt+0x0/0x8
06-03 13:29:12.999 1010315 31557 31557 W         : dump_stack+0xc8/0x14c
06-03 13:29:12.999 1010315 31557 31557 W         : warn_alloc+0x158/0x1c8
06-03 13:29:12.999 1010315 31557 31557 W         : __alloc_pages_slowpath+0x9d8/0xb80
06-03 13:29:12.999 1010315 31557 31557 W         : __alloc_pages_nodemask+0x1c4/0x430
06-03 13:29:12.999 1010315 31557 31557 W         : allocate_slab+0xb4/0x390
06-03 13:29:12.999 1010315 31557 31557 W         : ___slab_alloc+0x12c/0x3a4
06-03 13:29:12.999 1010315 31557 31557 W         : kmem_cache_alloc+0x358/0x5e4
06-03 13:29:12.999 1010315 31557 31557 W         : avc_alloc_node+0x30/0x184
06-03 13:29:12.999 1010315 31557 31557 W         : avc_update_node+0x54/0x4f0
06-03 13:29:12.999 1010315 31557 31557 W         : avc_has_extended_perms+0x1a4/0x460
06-03 13:29:12.999 1010315 31557 31557 W         : selinux_file_ioctl+0x320/0x3d0
06-03 13:29:12.999 1010315 31557 31557 W         : __arm64_sys_ioctl+0xec/0x1fc
06-03 13:29:12.999 1010315 31557 31557 W         : el0_svc_common+0xc0/0x24c
06-03 13:29:12.999 1010315 31557 31557 W         : el0_svc+0x28/0x88
06-03 13:29:12.999 1010315 31557 31557 W         : el0_sync_handler+0x8c/0xf0
06-03 13:29:12.999 1010315 31557 31557 W         : el0_sync+0x1a4/0x1c0
..
..
06-03 13:29:12.999 1010315 31557 31557 W SLUB    : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO)
06-03 13:29:12.999 1010315 31557 31557 W cache   : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0
06-03 13:29:12.999 1010315 31557 31557 W node 0  : slabs: 57, objs: 2907, free: 0
06-03 13:29:12.999 1010161 10686 10686 W SLUB    : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO)
06-03 13:29:12.999 1010161 10686 10686 W cache   : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0
06-03 13:29:12.999 1010161 10686 10686 W node 0  : slabs: 57, objs: 2907, free: 0
06-03 13:29:12.999 1010161 10686 10686 W SLUB    : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO)
06-03 13:29:12.999 1010161 10686 10686 W cache   : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0
06-03 13:29:12.999 1010161 10686 10686 W node 0  : slabs: 57, objs: 2907, free: 0
06-03 13:29:12.999 1010161 10686 10686 W SLUB    : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO)
06-03 13:29:12.999 1010161 10686 10686 W cache   : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0
06-03 13:29:12.999 1010161 10686 10686 W node 0  : slabs: 57, objs: 2907, free: 0
06-03 13:29:13.000 1010161 10686 10686 W SLUB    : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO)
06-03 13:29:13.000 1010161 10686 10686 W cache   : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0
06-03 13:29:13.000 1010161 10686 10686 W node 0  : slabs: 57, objs: 2907, free: 0
06-03 13:29:13.000 1010161 10686 10686 W SLUB    : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO)
06-03 13:29:13.000 1010161 10686 10686 W cache   : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0
06-03 13:29:13.000 1010161 10686 10686 W node 0  : slabs: 57, objs: 2907, free: 0
06-03 13:29:13.000 1010161 10686 10686 W SLUB    : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO)
06-03 13:29:13.000 1010161 10686 10686 W cache   : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0
06-03 13:29:13.000 1010161 10686 10686 W node 0  : slabs: 57, objs: 2907, free: 0
06-03 13:29:13.000 10230 30892 30892 W SLUB    : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO)
06-03 13:29:13.000 10230 30892 30892 W cache   : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0
06-03 13:29:13.000 10230 30892 30892 W node 0  : slabs: 57, objs: 2907, free: 0
06-03 13:29:13.000 10230 30892 30892 W SLUB    : Unable to allocate memory on node -1, gfp=0x900(GFP_NOWAIT|__GFP_ZERO)
06-03 13:29:13.000 10230 30892 30892 W cache   : avc_node, object size: 72, buffer size: 80, default order: 0, min order: 0

Based on [1], selinux is tolerate for failure of memory allocation.
Then, use __GFP_NOWARN together.

[1] 476accbe2f ("selinux: use GFP_NOWAIT in the AVC kmem_caches")

Signed-off-by: Minchan Kim <minchan@kernel.org>
[PM: subj fix, line wraps, normalized commit refs]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-19 09:44:49 +02:00
Mimi Zohar
912d16a2d7 evm: fix writing <securityfs>/evm overflow
[ Upstream commit 49219d9b87 ]

EVM_SETUP_COMPLETE is defined as 0x80000000, which is larger than INT_MAX.
The "-fno-strict-overflow" compiler option properly prevents signaling
EVM that the EVM policy setup is complete.  Define and read an unsigned
int.

Fixes: f00d797507 ("EVM: Allow userspace to signal an RSA key has been loaded")
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14 16:56:04 +02:00
Roberto Sassu
53124265fc evm: Refuse EVM_ALLOW_METADATA_WRITES only if an HMAC key is loaded
commit 9acc89d31f upstream.

EVM_ALLOW_METADATA_WRITES is an EVM initialization flag that can be set to
temporarily disable metadata verification until all xattrs/attrs necessary
to verify an EVM portable signature are copied to the file. This flag is
cleared when EVM is initialized with an HMAC key, to avoid that the HMAC is
calculated on unverified xattrs/attrs.

Currently EVM unnecessarily denies setting this flag if EVM is initialized
with a public key, which is not a concern as it cannot be used to trust
xattrs/attrs updates. This patch removes this limitation.

Fixes: ae1ba1676b ("EVM: Allow userland to permit modification of EVM-protected metadata")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Cc: stable@vger.kernel.org # 4.16.x
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-14 16:55:46 +02:00
Roberto Sassu
7b84c7d7e2 evm: Execute evm_inode_init_security() only when an HMAC key is loaded
commit 9eea290429 upstream.

evm_inode_init_security() requires an HMAC key to calculate the HMAC on
initial xattrs provided by LSMs. However, it checks generically whether a
key has been loaded, including also public keys, which is not correct as
public keys are not suitable to calculate the HMAC.

Originally, support for signature verification was introduced to verify a
possibly immutable initial ram disk, when no new files are created, and to
switch to HMAC for the root filesystem. By that time, an HMAC key should
have been loaded and usable to calculate HMACs for new files.

More recently support for requiring an HMAC key was removed from the
kernel, so that signature verification can be used alone. Since this is a
legitimate use case, evm_inode_init_security() should not return an error
when no HMAC key has been loaded.

This patch fixes this problem by replacing the evm_key_loaded() check with
a check of the EVM_INIT_HMAC flag in evm_initialized.

Fixes: 26ddabfe96 ("evm: enable EVM when X509 certificate is loaded")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Cc: stable@vger.kernel.org # 4.5.x
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-14 16:55:46 +02:00
Eric Snowberg
1573d595e2 integrity: Load mokx variables into the blacklist keyring
[ Upstream commit ebd9c2ae36 ]

During boot the Secure Boot Forbidden Signature Database, dbx,
is loaded into the blacklist keyring.  Systems booted with shim
have an equivalent Forbidden Signature Database called mokx.
Currently mokx is only used by shim and grub, the contents are
ignored by the kernel.

Add the ability to load mokx into the blacklist keyring during boot.

Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
Suggested-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
cc: keyrings@vger.kernel.org
Link: https://lore.kernel.org/r/c33c8e3839a41e9654f41cc92c7231104931b1d7.camel@HansenPartnership.com/
Link: https://lore.kernel.org/r/20210122181054.32635-5-eric.snowberg@oracle.com/ # v5
Link: https://lore.kernel.org/r/161428674320.677100.12637282414018170743.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/161433313205.902181.2502803393898221637.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161529607422.163428.13530426573612578854.stgit@warthog.procyon.org.uk/ # v3
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-30 08:47:30 -04:00
Eric Snowberg
45109066f6 certs: Add EFI_CERT_X509_GUID support for dbx entries
[ Upstream commit 56c5812623 ]

This fixes CVE-2020-26541.

The Secure Boot Forbidden Signature Database, dbx, contains a list of now
revoked signatures and keys previously approved to boot with UEFI Secure
Boot enabled.  The dbx is capable of containing any number of
EFI_CERT_X509_SHA256_GUID, EFI_CERT_SHA256_GUID, and EFI_CERT_X509_GUID
entries.

Currently when EFI_CERT_X509_GUID are contained in the dbx, the entries are
skipped.

Add support for EFI_CERT_X509_GUID dbx entries. When a EFI_CERT_X509_GUID
is found, it is added as an asymmetrical key to the .blacklist keyring.
Anytime the .platform keyring is used, the keys in the .blacklist keyring
are referenced, if a matching key is found, the key will be rejected.

[DH: Made the following changes:
 - Added to have a config option to enable the facility.  This allows a
   Kconfig solution to make sure that pkcs7_validate_trust() is
   enabled.[1][2]
 - Moved the functions out from the middle of the blacklist functions.
 - Added kerneldoc comments.]

Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
cc: Randy Dunlap <rdunlap@infradead.org>
cc: Mickaël Salaün <mic@digikod.net>
cc: Arnd Bergmann <arnd@kernel.org>
cc: keyrings@vger.kernel.org
Link: https://lore.kernel.org/r/20200901165143.10295-1-eric.snowberg@oracle.com/ # rfc
Link: https://lore.kernel.org/r/20200909172736.73003-1-eric.snowberg@oracle.com/ # v2
Link: https://lore.kernel.org/r/20200911182230.62266-1-eric.snowberg@oracle.com/ # v3
Link: https://lore.kernel.org/r/20200916004927.64276-1-eric.snowberg@oracle.com/ # v4
Link: https://lore.kernel.org/r/20210122181054.32635-2-eric.snowberg@oracle.com/ # v5
Link: https://lore.kernel.org/r/161428672051.677100.11064981943343605138.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/161433310942.902181.4901864302675874242.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161529605075.163428.14625520893961300757.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/bc2c24e3-ed68-2521-0bf4-a1f6be4a895d@infradead.org/ [1]
Link: https://lore.kernel.org/r/20210225125638.1841436-1-arnd@kernel.org/ [2]
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-30 08:47:30 -04:00
Colin Ian King
31c9a4b24d KEYS: trusted: Fix memory leak on object td
commit 83a775d5f9 upstream.

Two error return paths are neglecting to free allocated object td,
causing a memory leak. Fix this by returning via the error return
path that securely kfree's td.

Fixes clang scan-build warning:
security/keys/trusted-keys/trusted_tpm1.c:496:10: warning: Potential
memory leak [unix.Malloc]

Cc: stable@vger.kernel.org
Fixes: 5df16caada ("KEYS: trusted: Fix incorrect handling of tpm_get_random()")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-19 10:12:50 +02:00
Li Huafei
6b4b3b8404 ima: Fix the error code for restoring the PCR value
[ Upstream commit 7990ccafaa ]

In ima_restore_measurement_list(), hdr[HDR_PCR].data is pointing to a
buffer of type u8, which contains the dumped 32-bit pcr value.
Currently, only the least significant byte is used to restore the pcr
value. We should convert hdr[HDR_PCR].data to a pointer of type u32
before fetching the value to restore the correct pcr value.

Fixes: 47fdee60b4 ("ima: use ima_parse_buf() to parse measurements headers")
Signed-off-by: Li Huafei <lihuafei1@huawei.com>
Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-14 09:50:30 +02:00
James Bottomley
09a119a2d4 security: keys: trusted: fix TPM2 authorizations
[ Upstream commit de66514d93 ]

In TPM 1.2 an authorization was a 20 byte number.  The spec actually
recommended you to hash variable length passwords and use the sha1
hash as the authorization.  Because the spec doesn't require this
hashing, the current authorization for trusted keys is a 40 digit hex
number.  For TPM 2.0 the spec allows the passing in of variable length
passwords and passphrases directly, so we should allow that in trusted
keys for ease of use.  Update the 'blobauth' parameter to take this
into account, so we can now use plain text passwords for the keys.

so before

keyctl add trusted kmk "new 32 blobauth=f572d396fae9206628714fb2ce00f72e94f2258fkeyhandle=81000001" @u

after we will accept both the old hex sha1 form as well as a new
directly supplied password:

keyctl add trusted kmk "new 32 blobauth=hello keyhandle=81000001" @u

Since a sha1 hex code must be exactly 40 bytes long and a direct
password must be 20 or less, we use the length as the discriminator
for which form is input.

Note this is both and enhancement and a potential bug fix.  The TPM
2.0 spec requires us to strip leading zeros, meaning empyty
authorization is a zero length HMAC whereas we're currently passing in
20 bytes of zeros.  A lot of TPMs simply accept this as OK, but the
Microsoft TPM emulator rejects it with TPM_RC_BAD_AUTH, so this patch
makes the Microsoft TPM emulator work with trusted keys.

Fixes: 0fe5480303 ("keys, trusted: seal/unseal with TPM 2.0 chips")
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Tested-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-14 09:50:20 +02:00
Paul Moore
4c0ddc8712 selinux: add proper NULL termination to the secclass_map permissions
commit e4c82eafb6 upstream.

This patch adds the missing NULL termination to the "bpf" and
"perf_event" object class permission lists.

This missing NULL termination should really only affect the tools
under scripts/selinux, with the most important being genheaders.c,
although in practice this has not been an issue on any of my dev/test
systems.  If the problem were to manifest itself it would likely
result in bogus permissions added to the end of the object class;
thankfully with no access control checks using these bogus
permissions and no policies defining these permissions the impact
would likely be limited to some noise about undefined permissions
during policy load.

Cc: stable@vger.kernel.org
Fixes: ec27c3568a ("selinux: bpf: Add selinux check for eBPF syscall operations")
Fixes: da97e18458 ("perf_event: Add support for LSM and SELinux checks")
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-14 09:49:59 +02:00
Arnd Bergmann
f37b9c142e security: commoncap: fix -Wstringop-overread warning
commit 82e5d8cc76 upstream.

gcc-11 introdces a harmless warning for cap_inode_getsecurity:

security/commoncap.c: In function ‘cap_inode_getsecurity’:
security/commoncap.c:440:33: error: ‘memcpy’ reading 16 bytes from a region of size 0 [-Werror=stringop-overread]
  440 |                                 memcpy(&nscap->data, &cap->data, sizeof(__le32) * 2 * VFS_CAP_U32);
      |                                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The problem here is that tmpbuf is initialized to NULL, so gcc assumes
it is not accessible unless it gets set by vfs_getxattr_alloc().  This is
a legitimate warning as far as I can tell, but the code is correct since
it correctly handles the error when that function fails.

Add a separate NULL check to tell gcc about it as well.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: James Morris <jamorris@linux.microsoft.com>
Cc: Andrey Zhizhikin <andrey.z@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11 14:47:36 +02:00
James Bottomley
bf84ef2dd2 KEYS: trusted: Fix TPM reservation for seal/unseal
[ Upstream commit 9d5171eab4 ]

The original patch 8c657a0590 ("KEYS: trusted: Reserve TPM for seal
and unseal operations") was correct on the mailing list:

https://lore.kernel.org/linux-integrity/20210128235621.127925-4-jarkko@kernel.org/

But somehow got rebased so that the tpm_try_get_ops() in
tpm2_seal_trusted() got lost.  This causes an imbalanced put of the
TPM ops and causes oopses on TIS based hardware.

This fix puts back the lost tpm_try_get_ops()

Fixes: 8c657a0590 ("KEYS: trusted: Reserve TPM for seal and unseal operations")
Reported-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-28 13:39:59 +02:00
Ondrej Mosnacek
a28124e8ad selinux: fix race between old and new sidtab
commit 9ad6e9cb39 upstream.

Since commit 1b8b31a2e6 ("selinux: convert policy read-write lock to
RCU"), there is a small window during policy load where the new policy
pointer has already been installed, but some threads may still be
holding the old policy pointer in their read-side RCU critical sections.
This means that there may be conflicting attempts to add a new SID entry
to both tables via sidtab_context_to_sid().

See also (and the rest of the thread):
https://lore.kernel.org/selinux/CAFqZXNvfux46_f8gnvVvRYMKoes24nwm2n3sPbMjrB8vKTW00g@mail.gmail.com/

Fix this by installing the new policy pointer under the old sidtab's
spinlock along with marking the old sidtab as "frozen". Then, if an
attempt to add new entry to a "frozen" sidtab is detected, make
sidtab_context_to_sid() return -ESTALE to indicate that a new policy
has been installed and that the caller will have to abort the policy
transaction and try again after re-taking the policy pointer (which is
guaranteed to be a newer policy). This requires adding a retry-on-ESTALE
logic to all callers of sidtab_context_to_sid(), but fortunately these
are easy to determine and aren't that many.

This seems to be the simplest solution for this problem, even if it
looks somewhat ugly. Note that other places in the kernel (e.g.
do_mknodat() in fs/namei.c) use similar stale-retry patterns, so I think
it's reasonable.

Cc: stable@vger.kernel.org
Fixes: 1b8b31a2e6 ("selinux: convert policy read-write lock to RCU")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-14 08:41:57 +02:00
Ondrej Mosnacek
fd75d73aa2 selinux: fix cond_list corruption when changing booleans
commit d8f5f0ea5b upstream.

Currently, duplicate_policydb_cond_list() first copies the whole
conditional avtab and then tries to link to the correct entries in
cond_dup_av_list() using avtab_search(). However, since the conditional
avtab may contain multiple entries with the same key, this approach
often fails to find the right entry, potentially leading to wrong rules
being activated/deactivated when booleans are changed.

To fix this, instead start with an empty conditional avtab and add the
individual entries one-by-one while building the new av_lists. This
approach leads to the correct result, since each entry is present in the
av_lists exactly once.

The issue can be reproduced with Fedora policy as follows:

    # sesearch -s ftpd_t -t public_content_rw_t -c dir -p create -A
    allow ftpd_t non_security_file_type:dir { add_name create getattr ioctl link lock open read remove_name rename reparent rmdir search setattr unlink watch watch_reads write }; [ ftpd_full_access ]:True
    allow ftpd_t public_content_rw_t:dir { add_name create link remove_name rename reparent rmdir setattr unlink watch watch_reads write }; [ ftpd_anon_write ]:True
    # setsebool ftpd_anon_write=off ftpd_connect_all_unreserved=off ftpd_connect_db=off ftpd_full_access=off

On fixed kernels, the sesearch output is the same after the setsebool
command:

    # sesearch -s ftpd_t -t public_content_rw_t -c dir -p create -A
    allow ftpd_t non_security_file_type:dir { add_name create getattr ioctl link lock open read remove_name rename reparent rmdir search setattr unlink watch watch_reads write }; [ ftpd_full_access ]:True
    allow ftpd_t public_content_rw_t:dir { add_name create link remove_name rename reparent rmdir setattr unlink watch watch_reads write }; [ ftpd_anon_write ]:True

While on the broken kernels, it will be different:

    # sesearch -s ftpd_t -t public_content_rw_t -c dir -p create -A
    allow ftpd_t non_security_file_type:dir { add_name create getattr ioctl link lock open read remove_name rename reparent rmdir search setattr unlink watch watch_reads write }; [ ftpd_full_access ]:True
    allow ftpd_t non_security_file_type:dir { add_name create getattr ioctl link lock open read remove_name rename reparent rmdir search setattr unlink watch watch_reads write }; [ ftpd_full_access ]:True
    allow ftpd_t non_security_file_type:dir { add_name create getattr ioctl link lock open read remove_name rename reparent rmdir search setattr unlink watch watch_reads write }; [ ftpd_full_access ]:True

While there, also simplify the computation of nslots. This changes the
nslots values for nrules 2 or 3 to just two slots instead of 4, which
makes the sequence more consistent.

Cc: stable@vger.kernel.org
Fixes: c7c556f1e8 ("selinux: refactor changing booleans")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-14 08:41:57 +02:00
Ondrej Mosnacek
4f29b08e23 selinux: make nslot handling in avtab more robust
commit 442dc00f82 upstream.

1. Make sure all fileds are initialized in avtab_init().
2. Slightly refactor avtab_alloc() to use the above fact.
3. Use h->nslot == 0 as a sentinel in the access functions to prevent
   dereferencing h->htable when it's not allocated.

Cc: stable@vger.kernel.org
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-14 08:41:57 +02:00
Mimi Zohar
546f7fcc45 integrity: double check iint_cache was initialized
commit 92063f3ca7 upstream.

The kernel may be built with multiple LSMs, but only a subset may be
enabled on the boot command line by specifying "lsm=".  Not including
"integrity" on the ordered LSM list may result in a NULL deref.

As reported by Dmitry Vyukov:
in qemu:
qemu-system-x86_64       -enable-kvm     -machine q35,nvdimm -cpu
max,migratable=off -smp 4       -m 4G,slots=4,maxmem=16G        -hda
wheezy.img      -kernel arch/x86/boot/bzImage   -nographic -vga std
 -soundhw all     -usb -usbdevice tablet  -bt hci -bt device:keyboard
   -net user,host=10.0.2.10,hostfwd=tcp::10022-:22 -net
nic,model=virtio-net-pci   -object
memory-backend-file,id=pmem1,share=off,mem-path=/dev/zero,size=64M
  -device nvdimm,id=nvdimm1,memdev=pmem1  -append "console=ttyS0
root=/dev/sda earlyprintk=serial rodata=n oops=panic panic_on_warn=1
panic=86400 lsm=smack numa=fake=2 nopcid dummy_hcd.num=8"   -pidfile
vm_pid -m 2G -cpu host

But it crashes on NULL deref in integrity_inode_get during boot:

Run /sbin/init as init process
BUG: kernel NULL pointer dereference, address: 000000000000001c
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 3 PID: 1 Comm: swapper/0 Not tainted 5.12.0-rc2+ #97
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
rel-1.13.0-44-g88ab0c15525c-prebuilt.qemu.org 04/01/2014
RIP: 0010:kmem_cache_alloc+0x2b/0x370 mm/slub.c:2920
Code: 57 41 56 41 55 41 54 41 89 f4 55 48 89 fd 53 48 83 ec 10 44 8b
3d d9 1f 90 0b 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 31 c0 <8b> 5f
1c 4cf
RSP: 0000:ffffc9000032f9d8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888017fc4f00 RCX: 0000000000000000
RDX: ffff888040220000 RSI: 0000000000000c40 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffff888019263627
R10: ffffffff83937cd1 R11: 0000000000000000 R12: 0000000000000c40
R13: ffff888019263538 R14: 0000000000000000 R15: 0000000000ffffff
FS:  0000000000000000(0000) GS:ffff88802d180000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000000001c CR3: 000000000b48e000 CR4: 0000000000750ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 integrity_inode_get+0x47/0x260 security/integrity/iint.c:105
 process_measurement+0x33d/0x17e0 security/integrity/ima/ima_main.c:237
 ima_bprm_check+0xde/0x210 security/integrity/ima/ima_main.c:474
 security_bprm_check+0x7d/0xa0 security/security.c:845
 search_binary_handler fs/exec.c:1708 [inline]
 exec_binprm fs/exec.c:1761 [inline]
 bprm_execve fs/exec.c:1830 [inline]
 bprm_execve+0x764/0x19a0 fs/exec.c:1792
 kernel_execve+0x370/0x460 fs/exec.c:1973
 try_to_run_init_process+0x14/0x4e init/main.c:1366
 kernel_init+0x11d/0x1b8 init/main.c:1477
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Modules linked in:
CR2: 000000000000001c
---[ end trace 22d601a500de7d79 ]---

Since LSMs and IMA may be configured at build time, but not enabled at
run time, panic the system if "integrity" was not initialized before use.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Fixes: 79f7865d84 ("LSM: Introduce "lsm=" for boottime LSM selection")
Cc: stable@vger.kernel.org
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-30 14:31:55 +02:00
Ondrej Mosnacek
19c9967e49 selinux: fix variable scope issue in live sidtab conversion
commit 6406887a12 upstream.

Commit 02a52c5c8c ("selinux: move policy commit after updating
selinuxfs") moved the selinux_policy_commit() call out of
security_load_policy() into sel_write_load(), which caused a subtle yet
rather serious bug.

The problem is that security_load_policy() passes a reference to the
convert_params local variable to sidtab_convert(), which stores it in
the sidtab, where it may be accessed until the policy is swapped over
and RCU synchronized. Before 02a52c5c8c, selinux_policy_commit() was
called directly from security_load_policy(), so the convert_params
pointer remained valid all the way until the old sidtab was destroyed,
but now that's no longer the case and calls to sidtab_context_to_sid()
on the old sidtab after security_load_policy() returns may cause invalid
memory accesses.

This can be easily triggered using the stress test from commit
ee1a84fdfe ("selinux: overhaul sidtab to fix bug and improve
performance"):
```
function rand_cat() {
	echo $(( $RANDOM % 1024 ))
}

function do_work() {
	while true; do
		echo -n "system_u:system_r:kernel_t:s0:c$(rand_cat),c$(rand_cat)" \
			>/sys/fs/selinux/context 2>/dev/null || true
	done
}

do_work >/dev/null &
do_work >/dev/null &
do_work >/dev/null &

while load_policy; do echo -n .; sleep 0.1; done

kill %1
kill %2
kill %3
```

Fix this by allocating the temporary sidtab convert structures
dynamically and passing them among the
selinux_policy_{load,cancel,commit} functions.

Fixes: 02a52c5c8c ("selinux: move policy commit after updating selinuxfs")
Cc: stable@vger.kernel.org
Tested-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
[PM: merge fuzz in security.h and services.c]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-30 14:31:53 +02:00
Ondrej Mosnacek
9731e08a33 selinux: don't log MAC_POLICY_LOAD record on failed policy load
commit 519dad3bcd upstream.

If sel_make_policy_nodes() fails, we should jump to 'out', not 'out1',
as the latter would incorrectly log an MAC_POLICY_LOAD audit record,
even though the policy hasn't actually been reloaded. The 'out1' jump
label now becomes unused and can be removed.

Fixes: 02a52c5c8c ("selinux: move policy commit after updating selinuxfs")
Cc: stable@vger.kernel.org
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-30 14:31:53 +02:00
Eric W. Biederman
5d5422a294 Revert 95ebabde38 ("capabilities: Don't allow writing ambiguous v3 file capabilities")
commit 3b0c2d3eaa upstream.

It turns out that there are in fact userspace implementations that
care and this recent change caused a regression.

https://github.com/containers/buildah/issues/3071

As the motivation for the original change was future development,
and the impact is existing real world code just revert this change
and allow the ambiguity in v3 file caps.

Cc: stable@vger.kernel.org
Fixes: 95ebabde38 ("capabilities: Don't allow writing ambiguous v3 file capabilities")
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 17:06:27 +01:00
Tetsuo Handa
aa40f5e33c tomoyo: recognize kernel threads correctly
commit 9c83465f32 upstream.

Commit db68ce10c4 ("new helper: uaccess_kernel()") replaced
segment_eq(get_fs(), KERNEL_DS) with uaccess_kernel(). But the correct
method for tomoyo to check whether current is a kernel thread in order
to assume that kernel threads are privileged for socket operations was
(current->flags & PF_KTHREAD). Now that uaccess_kernel() became 0 on x86,
tomoyo has to fix this problem. Do like commit 942cb357ae ("Smack:
Handle io_uring kernel thread privileges") does.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-09 11:11:15 +01:00
Tetsuo Handa
e00420943a tomoyo: ignore data race while checking quota
commit 5797e861e4 upstream.

syzbot is reporting that tomoyo's quota check is racy [1]. But this check
is tolerant of some degree of inaccuracy. Thus, teach KCSAN to ignore
this data race.

[1] https://syzkaller.appspot.com/bug?id=999533deec7ba6337f8aa25d8bd1a4d5f7e50476

Reported-by: syzbot <syzbot+0789a72b46fd91431bd8@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-07 12:34:05 +01:00
Sabyrzhan Tasbolatov
fa5b656092 smackfs: restrict bytes count in smackfs write functions
commit 7ef4c19d24 upstream.

syzbot found WARNINGs in several smackfs write operations where
bytes count is passed to memdup_user_nul which exceeds
GFP MAX_ORDER. Check count size if bigger than PAGE_SIZE.

Per smackfs doc, smk_write_net4addr accepts any label or -CIPSO,
smk_write_net6addr accepts any label or -DELETE. I couldn't find
any general rule for other label lengths except SMK_LABELLEN,
SMK_LONGLABEL, SMK_CIPSOMAX which are documented.

Let's constrain, in general, smackfs label lengths for PAGE_SIZE.
Although fuzzer crashes write to smackfs/netlabel on 0x400000 length.

Here is a quick way to reproduce the WARNING:
python -c "print('A' * 0x400000)" > /sys/fs/smackfs/netlabel

Reported-by: syzbot+a71a442385a0b2815497@syzkaller.appspotmail.com
Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@gmail.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-07 12:34:05 +01:00
Jarkko Sakkinen
67118bb78d KEYS: trusted: Reserve TPM for seal and unseal operations
commit 8c657a0590 upstream.

When TPM 2.0 trusted keys code was moved to the trusted keys subsystem,
the operations were unwrapped from tpm_try_get_ops() and tpm_put_ops(),
which are used to take temporarily the ownership of the TPM chip. The
ownership is only taken inside tpm_send(), but this is not sufficient,
as in the key load TPM2_CC_LOAD, TPM2_CC_UNSEAL and TPM2_FLUSH_CONTEXT
need to be done as a one single atom.

Take the TPM chip ownership before sending anything with
tpm_try_get_ops() and tpm_put_ops(), and use tpm_transmit_cmd() to send
TPM commands instead of tpm_send(), reverting back to the old behaviour.

Fixes: 2e19e10131 ("KEYS: trusted: Move TPM2 trusted keys code")
Reported-by: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: stable@vger.kernel.org
Cc: David Howells <dhowells@redhat.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Sumit Garg <sumit.garg@linaro.org>
Acked-by Sumit Garg <sumit.garg@linaro.org>
Tested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 11:38:29 +01:00
Jarkko Sakkinen
54c527c18e KEYS: trusted: Fix migratable=1 failing
commit 8da7520c80 upstream.

Consider the following transcript:

$ keyctl add trusted kmk "new 32 blobauth=helloworld keyhandle=80000000 migratable=1" @u
add_key: Invalid argument

The documentation has the following description:

  migratable=   0|1 indicating permission to reseal to new PCR values,
                default 1 (resealing allowed)

The consequence is that "migratable=1" should succeed. Fix this by
allowing this condition to pass instead of return -EINVAL.

[*] Documentation/security/keys/trusted-encrypted.rst

Cc: stable@vger.kernel.org
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Fixes: d00a1c72f7 ("keys: add new trusted key-type")
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 11:38:29 +01:00
Jarkko Sakkinen
9d83cc1a1e KEYS: trusted: Fix incorrect handling of tpm_get_random()
commit 5df16caada upstream.

When tpm_get_random() was introduced, it defined the following API for the
return value:

1. A positive value tells how many bytes of random data was generated.
2. A negative value on error.

However, in the call sites the API was used incorrectly, i.e. as it would
only return negative values and otherwise zero. Returning he positive read
counts to the user space does not make any possible sense.

Fix this by returning -EIO when tpm_get_random() returns a positive value.

Fixes: 41ab999c80 ("tpm: Move tpm_get_random api into the TPM device driver")
Cc: stable@vger.kernel.org
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Kent Yoder <key@linux.vnet.ibm.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 11:38:29 +01:00
Amir Goldstein
2fe9215301 selinux: fix inconsistency between inode_getxattr and inode_listsecurity
commit a9ffe682c5 upstream.

When inode has no listxattr op of its own (e.g. squashfs) vfs_listxattr
calls the LSM inode_listsecurity hooks to list the xattrs that LSMs will
intercept in inode_getxattr hooks.

When selinux LSM is installed but not initialized, it will list the
security.selinux xattr in inode_listsecurity, but will not intercept it
in inode_getxattr.  This results in -ENODATA for a getxattr call for an
xattr returned by listxattr.

This situation was manifested as overlayfs failure to copy up lower
files from squashfs when selinux is built-in but not initialized,
because ovl_copy_xattr() iterates the lower inode xattrs by
vfs_listxattr() and vfs_getxattr().

Match the logic of inode_listsecurity to that of inode_getxattr and
do not list the security.selinux xattr if selinux is not initialized.

Reported-by: Michael Labriola <michael.d.labriola@gmail.com>
Tested-by: Michael Labriola <michael.d.labriola@gmail.com>
Link: https://lore.kernel.org/linux-unionfs/2nv9d47zt7.fsf@aldarion.sourceruckus.org/
Fixes: c8e222616c ("selinux: allow reading labels before policy is loaded")
Cc: stable@vger.kernel.org#v5.9+
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 11:38:28 +01:00
David Howells
d7b0efadc3 certs: Fix blacklist flag type confusion
[ Upstream commit 4993e1f947 ]

KEY_FLAG_KEEP is not meant to be passed to keyring_alloc() or key_alloc(),
as these only take KEY_ALLOC_* flags.  KEY_FLAG_KEEP has the same value as
KEY_ALLOC_BYPASS_RESTRICTION, but fortunately only key_create_or_update()
uses it.  LSMs using the key_alloc hook don't check that flag.

KEY_FLAG_KEEP is then ignored but fortunately (again) the root user cannot
write to the blacklist keyring, so it is not possible to remove a key/hash
from it.

Fix this by adding a KEY_ALLOC_SET_KEEP flag that tells key_alloc() to set
KEY_FLAG_KEEP on the new key.  blacklist_init() can then, correctly, pass
this to keyring_alloc().

We can also use this in ima_mok_init() rather than setting the flag
manually.

Note that this doesn't fix an observable bug with the current
implementation but it is required to allow addition of new hashes to the
blacklist in the future without making it possible for them to be removed.

Fixes: 734114f878 ("KEYS: Add a system blacklist keyring")
Reported-by: Mickaël Salaün <mic@linux.microsoft.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Mickaël Salaün <mic@linux.microsoft.com>
cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04 11:37:59 +01:00
Gabriel Krisman Bertazi
6e223a3d90 watch_queue: Drop references to /dev/watch_queue
[ Upstream commit 8fe62e0c0e ]

The merged API doesn't use a watch_queue device, but instead relies on
pipes, so let the documentation reflect that.

Fixes: f7e47677e3 ("watch_queue: Add a key/keyring notification facility")
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: Ben Boeckel <mathstuf@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04 11:37:59 +01:00
Eric W. Biederman
54b4e5df95 capabilities: Don't allow writing ambiguous v3 file capabilities
[ Upstream commit 95ebabde38 ]

The v3 file capabilities have a uid field that records the filesystem
uid of the root user of the user namespace the file capabilities are
valid in.

When someone is silly enough to have the same underlying uid as the
root uid of multiple nested containers a v3 filesystem capability can
be ambiguous.

In the spirit of don't do that then, forbid writing a v3 filesystem
capability if it is ambiguous.

Fixes: 8db6c34f1d ("Introduce v3 namespaced file capabilities")
Reviewed-by: Andrew G. Morgan <morgan@kernel.org>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04 11:37:52 +01:00
Lakshmi Ramasubramanian
c365d333e9 ima: Free IMA measurement buffer after kexec syscall
[ Upstream commit f31e3386a4 ]

IMA allocates kernel virtual memory to carry forward the measurement
list, from the current kernel to the next kernel on kexec system call,
in ima_add_kexec_buffer() function.  This buffer is not freed before
completing the kexec system call resulting in memory leak.

Add ima_buffer field in "struct kimage" to store the virtual address
of the buffer allocated for the IMA measurement list.
Free the memory allocated for the IMA measurement list in
kimage_file_post_load_cleanup() function.

Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Suggested-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Fixes: 7b8589cc29 ("ima: on soft reboot, save the measurement list")
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04 11:37:50 +01:00
Lakshmi Ramasubramanian
1facf2415b ima: Free IMA measurement buffer on error
[ Upstream commit 6d14c65178 ]

IMA allocates kernel virtual memory to carry forward the measurement
list, from the current kernel to the next kernel on kexec system call,
in ima_add_kexec_buffer() function.  In error code paths this memory
is not freed resulting in memory leak.

Free the memory allocated for the IMA measurement list in
the error code paths in ima_add_kexec_buffer() function.

Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Suggested-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Fixes: 7b8589cc29 ("ima: on soft reboot, save the measurement list")
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04 11:37:50 +01:00
Dinghao Liu
494e9ec12c evm: Fix memleak in init_desc
[ Upstream commit ccf11dbaa0 ]

tmp_tfm is allocated, but not freed on subsequent kmalloc failure, which
leads to a memory leak.  Free tmp_tfm.

Fixes: d46eb36995 ("evm: crypto hash replaced by shash")
Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
[zohar@linux.ibm.com: formatted/reworded patch description]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04 11:37:40 +01:00
Miklos Szeredi
02dee03d48 cap: fix conversions on getxattr
[ Upstream commit f2b00be488 ]

If a capability is stored on disk in v2 format cap_inode_getsecurity() will
currently return in v2 format unconditionally.

This is wrong: v2 cap should be equivalent to a v3 cap with zero rootid,
and so the same conversions performed on it.

If the rootid cannot be mapped, v3 is returned unconverted.  Fix this so
that both v2 and v3 return -EOVERFLOW if the rootid (or the owner of the fs
user namespace in case of v2) cannot be mapped into the current user
namespace.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-02-17 11:02:22 +01:00
Al Viro
a3fddad7af dump_common_audit_data(): fix racy accesses to ->d_name
commit d36a1dd9f7 upstream.

We are not guaranteed the locking environment that would prevent
dentry getting renamed right under us.  And it's possible for
old long name to be freed after rename, leading to UAF here.

Cc: stable@kernel.org # v2.6.2+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-19 18:27:29 +01:00
Roberto Sassu
0f2206e3d9 ima: Don't modify file descriptor mode on the fly
commit 207cdd565d upstream.

Commit a408e4a86b ("ima: open a new file instance if no read
permissions") already introduced a second open to measure a file when the
original file descriptor does not allow it. However, it didn't remove the
existing method of changing the mode of the original file descriptor, which
is still necessary if the current process does not have enough privileges
to open a new one.

Changing the mode isn't really an option, as the filesystem might need to
do preliminary steps to make the read possible. Thus, this patch removes
the code and keeps the second open as the only option to measure a file
when it is unreadable with the original file descriptor.

Cc: <stable@vger.kernel.org> # 4.20.x: 0014cc04e8 ima: Set file->f_mode
Fixes: 2fe5d6def1 ("ima: integrity appraisal extension")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30 11:54:17 +01:00